"Gabrielle has returned to Washington to support a bipartisan bill to prevent economic crisis," read a message posted to Giffords' Twitter account while members began casting their votes on the House floor.

Minutes later, the three-term congresswoman, 41, slowly entered the chamber to loud, sustained applause and a standing ovation by her colleagues, who huddled around her to give hugs, kisses and handshakes.

"You know we've had in this fight the most grizzled, hardened hearts harden even further and they all melted when she walked in the chamber," Rep. Debbie Wasserman Schultz, D-Fla., told ABC's Robin Roberts. "I've never heard, we have a lot of applause for various reasons in the House chamber, never like this. It was thunderous."

Vice President Joe Biden, with a big smile on his face, walked to the House floor and said, "I came to see Gabby, that's why I'm here."

In the hallway just outside, Giffords' husband, astronaut Mark Kelly, was all smiles as well.

"It feels good," he said as his wife was casting her first vote since the tragedy. "Great actually."

Democratic Minority Leader Nancy Pelosi of California said of Giffords as she was leaving the House floor Monday, "It was above and beyond the call of duty. She's a heroine ... an inspiration."

Pelosi said she had known Giffords was coming to the Hill for this vote for some time, but didn't want to say anything until it happened. The two spent some time on the floor talking Monday evening.

"We had our girl talk. Had girls' hugs and all of that. So it was pretty thrilling, personally and officially," Pelosi said. "She honored us with her presence."

Congresswoman Schultz said she was most impressed by the Giffords' progress.

"It's one thing for her to see and recognize friends of hers and close colleagues; she walked up into the Capitol and when she saw Bill Livingood, our sergeant-at-arms, she said, 'Livingood,' and gave him a big hug. It was just amazing, it really was."

Biden said he and Giffords "commiserated about the steps of recovery."

"She's remarkable," Biden said. "Will matters. She is the embodiment of a strong, strong, strong woman. Think about what she's been through. And think about her determination."

Asked about any plans for Giffords to go to the White House, Biden didn't rule it out but wouldn't comment.

"It's inappropriate for me to talk about her schedule," Biden said.

Giffords spokesman C.J. Karamargin told Tucson Weekly in an email that "the congresswoman insisted on participating."

"Congresswoman Giffords has been following this debate closely over the past two weeks," she said. "Like the vast majority of Americans, she is extremely disappointed at Washington's inability to confront the debt ceiling issue in a timely and thoughtful manner."

Escorted by her husband and Schultz, Giffords exited the House floor slowly, giving a small wave to people as she left. She left the Capitol in an SUV shortly thereafter.

She said Giffords decided to make the trip to Washington because she "wanted to make sure that her district had a voice in this important vote."

Giffords Returns to Congress

Schultz told Roberts this morning that Giffords has emphasized a need for balance and stability throughout her career in politics and that concern for ensuring "the safety net wouldn't be lost from our seniors" drove her to the floor that night.

"You know, Arizona has a lot of seniors like South Florida does, and it was just, you know, all the way around, she's a representative and a daughter of Tucson, Ariz., and made a triumphant return yesterday and it was incredible."

When Biden was asked what he spoke with Giffords about, he joked, "She's now a member of the cracked head club like me."

The debt-ceiling bill passed the House 269-161. The Senate will vote on the measure today.